High-density plant cultivation systems and related apparatuses and methods

ABSTRACT

A gravity-driven plant cultivation system includes: (a) a frame; (b) a plurality of vertically stacked conveyor assemblies mounted to the frame. Each conveyor assembly includes at least one gravity conveyor extending along a conveyor axis. The conveyor axis slopes downwards relative to a horizontal plane from a frame upstream end to a frame downstream end of the frame. The system further includes (c) a plurality of plant cultivation trays rollingly supported on each gravity conveyor and urged to translate along a respective conveyor axis toward the frame downstream end via gravitational force.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/625,014, filed on Feb. 1, 2018, the entirety of which is incorporatedherein by reference.

FIELD

The disclosure relates generally to plant cultivation. Morespecifically, the disclosure relates to high-density, vertically-stackedplant cultivation systems and related apparatuses and methods.

BACKGROUND

U.S. Pat. App. Pub. No. 2017/0027112 (Vail et al.) discloses an indoorfarming module system. The indoor farming module system may comprise ahousing. Additionally, the indoor farming module system may comprise aplurality of indoor farming module components within the housing, theplurality of indoor farming module components comprising a high-densityracking system having a plurality of vertical levels within the housing,wherein a vertical distance between two adjacent vertical levels is notmore than 11 inches; an airflow management lighting system, wherein theairflow management lighting system provides airflow and lighting to eachlevel of the plurality of vertical levels; an irrigation system; and arecirculation system.

U.S. Pat. No. 4,854,075 (Greiling) discloses a plant tray having aplurality of cups in a flat sheet of moldable material wherein the cupsare in parallel rows with at least some of the rows having spacesbetween some of the cups for air openings in the flat sheet to supplyair to the foliage of plants growing in the cups. The cups in adjacentrows may be offset and have a variable width shape such as a hexagon toprovide a maximum number of cups in the available space and which arelocated close to the air openings. The cups of hexagonal cross sectionalso have corners for directing the root growth of the plants. Thesidewalls of adjacent cups surrounding the air openings form funnels forimproved air drainage.

U.S. Pat. No. 4,495,725 (Talbott) discloses an apparatus for growingplants having a floor with a plurality of raised projections definingtrough regions therebetween and being adapted to hold plant wateringfluid at a level relative to the upper periphery of the projections. Aninsert for the pan is also provided, having a plurality of spaced,downwardly extending cells, each cell including a bottom defining anopening. The insert is shiftable between a first position and a secondposition. The first position is one in which the bottoms are disposed inthe trough regions below the level of the watering fluid so that thefluid can enter the openings. In the second position, at least some ofthe bottoms rest upon the projections so that the openings are less thanfully obstructed by the projections and so that fluid within the cellscan drain therefrom.

SUMMARY

The following summary is intended to introduce the reader to variousaspects of the applicant's teaching, but not to define any invention.

According to some aspects, a gravity-driven plant cultivation systemincludes: (a) a frame having a frame upstream end and a frame downstreamend spaced horizontally apart from the frame upstream end; and (b) aplurality of vertically stacked conveyor assemblies mounted to theframe. Each conveyor assembly includes at least one gravity conveyorextending between the frame upstream end and the frame downstream endalong a conveyor axis. The conveyor axis slopes downwards relative to ahorizontal plane from the frame upstream end to the frame downstreamend. The system further includes (c) a plurality of plant cultivationtrays rollingly supported on each gravity conveyor and urged totranslate along a respective conveyor axis toward the frame downstreamend via gravitational force. Each tray includes: (i) a tray body havinga tray top and a tray bottom vertically opposite the tray top; (ii) aplurality of plant cavities in the tray body and open to the tray top,the plant cavities for holding plants; and (iii) a nutrient chamberinternal the tray body and in fluid communication with the plantcavities, the nutrient chamber for holding plant nutrient solution.

In some examples, each gravity conveyor includes a pair of supportsspaced laterally apart from one another by a conveyor opening. Each traysupport includes a rail extending between the frame downstream end andthe frame upstream end generally parallel with a respective conveyoraxis, and a plurality of wheels rotatably mounted to the rail and spacedapart from one another along the conveyor axis. The wheels of the pairof supports engage laterally spaced apart tray underside surfaces of theplant cultivation trays supported on the conveyor. Each tray undersidesurface slopes downwardly relative to the horizontal plane generallyparallel with the conveyor axis.

In some examples, the tray body includes a nutrient chamber bottom walllying in a bottom wall plane and a nutrient chamber sidewall extendingupwardly from a periphery of the nutrient chamber bottom wall. Thenutrient chamber bottom wall and the nutrient chamber sidewall enclosethe nutrient chamber. The nutrient chamber bottom wall is generallyparallel with the horizontal plane for maintaining a generally constantdepth of the plant nutrient solution across the nutrient chamber bottomwall.

In some examples, the nutrient chamber is laterally intermediate thepair of tray supports. In some examples, the nutrient chamber extendsinto the conveyor opening.

In some examples, each tray includes at least one tray vent passingthrough the tray body. The tray vent extends along a vertical vent axisnormal to the horizontal plane between a vent top end open to the traytop and a vent bottom end open to the tray bottom. The tray vent is forpassing air through the tray body to facilitate delivery of air to theplants from below. In some examples, the tray vent passes through thenutrient chamber.

In some examples, the system further includes an air delivery ductworkfor delivering air to the plants. The air delivery ductwork includes aplurality of first ports above each plant cultivation tray fordischarging air from the air delivery ductwork downwardly to deliver airto the plants from above, and a plurality second ports below each plantcultivation tray for discharging air from the air delivery ductworkupwardly to deliver air to the plants from below via the tray vents.

According to some aspects, a plant cultivation tray for a gravity-drivenplant cultivation system includes: (a) a tray body having a tray top, atray bottom vertically opposite the tray top, a tray front, and a trayrear axially opposite the tray front. The tray body includes: (i) a pairof laterally spaced apart tray underside surfaces for engagement withwheels of a gravity conveyor to rollingly support the plant cultivationtray thereon. Each underside surface slopes downwards relative to ahorizontal plane from the tray rear to the tray front when the tray issupported on the conveyor. The tray body further includes (ii) anutrient chamber bottom wall lying in a bottom wall plane; and (iii) anutrient chamber sidewall extending upwardly from a periphery of thenutrient chamber bottom wall. The nutrient chamber bottom wall and thenutrient chamber sidewall enclose a nutrient chamber internal the traybody for holding plant nutrient solution. The nutrient chamber bottomwall is generally parallel with the horizontal plane when the tray issupported on the conveyor for maintaining a generally constant depth ofthe plant nutrient solution across the nutrient chamber bottom wall. Theplant cultivation tray further includes (b) a plurality of plantcavities in the tray body for holding plants. The plant cavities areopen to the tray top and in fluid communication with the nutrientchamber for providing the plant nutrient solution to the plants.

In some examples, the nutrient chamber bottom wall is laterallyintermediate and at an elevation below the underside surfaces.

In some examples, the tray includes at least one tray vent passingthrough the tray body. The tray vent extends along a vertical vent axisnormal to the horizontal plane between a vent top end open to the traytop and a vent bottom end open to the tray bottom. The tray vent is forpassing air through the tray body to facilitate delivery of air to theplants from below. In some examples, the tray vent passes through thenutrient chamber.

In some examples, each plant cavity extends along a vertical cavity axisnormal to the horizontal plane between a cavity top end open to the traytop and a cavity bottom end below the cavity top end. In some examples,the cavity bottom end of each plant cavity lies in a common cavitybottom plane, the cavity bottom plane generally parallel with thehorizontal plane when the tray is supported on the gravity conveyor. Insome examples, the cavity top end of each plant cavity lies in a commoncavity top plane, the cavity top plane generally parallel with thehorizontal plane when the tray is supported on the gravity conveyor.

According to some aspects, a method of operating a high-density plantcultivation system includes: (a) rollingly supporting a plurality ofplant cultivation trays holding plants on a gravity conveyor, thegravity conveyor extending along a conveyor axis between a frameupstream end and a frame downstream end, the conveyor axis slopingdownwardly relative to a horizontal plane from the frame upstream end tothe frame downstream end; (b) delivering air, plant nutrient solution,and light to the plants to facilitate plant growth; and (c) rolling theplant cultivation trays supported on the gravity conveyor along theconveyor axis toward the frame downstream end via gravitational force.

In some examples, the method further includes: supplying the plantnutrient solution to a nutrient chamber internal each tray, the nutrientchamber in fluid communication with the plants and enclosed from belowby a nutrient chamber bottom wall of the tray, the nutrient chamberbottom wall lying in a bottom wall plane, and during steps (a) to (c),maintaining the bottom wall plane generally parallel with the horizontalplane.

According to some aspects, a plant cultivation system includes: (a) aframe having a frame upstream end and a frame downstream end spacedhorizontally apart from the frame upstream end; and (b) a plurality ofvertically stacked conveyor assemblies mounted to the frame. Eachconveyor assembly includes at least one conveyor extending between theframe upstream end and the frame downstream end along a conveyor axis.The system further includes (c) a plurality of plant cultivation trayssupported on each conveyor for translation along a respective conveyoraxis toward the frame downstream end. Each plant cultivation trayincludes: (i) a tray body having a tray top and a tray bottom verticallyopposite the tray top; (ii) a plurality of plant cavities in the traybody and open to the tray top, the plant cavities for holding plants;and (iii) at least one tray vent passing vertically through the traybody, the tray vent open to the tray top and the tray bottom for passingair vertically through the tray body to facilitate delivery of air tothe plants from below. The system further includes (d) an air deliveryductwork for delivering air to the plants. The air delivery ductworkincludes a plurality of first ports above each plant cultivation trayfor discharging air from the air delivery ductwork downwardly to deliverair to the plants from above, and a plurality second ports below eachplant cultivation tray for discharging air from the air deliveryductwork upwardly to deliver air to the plants from below via the trayvents.

In some examples, each tray vent extends between a vent top end open tothe tray top and a vent bottom end open to the tray bottom, and the ventbottom end overlies at least one of the second ports for receiving airdischarged from the at least one of the second ports.

In some examples, each plant cultivation tray includes a nutrientchamber internal the tray body and in fluid communication with the plantcavities. The nutrient chamber is for holding plant nutrient solution.In some examples, the tray vent passes vertically through the nutrientchamber.

In some examples, each tray includes a tray sidewall extending betweenthe tray top and the tray bottom, the tray sidewall having ahorizontally outwardly directed sidewall outer surface and at least onevent recess extending horizontally inward of the sidewall outer surfaceand open to the tray top and the tray bottom. In some examples, the trayvent comprises the vent recess.

In some examples, each conveyor includes a pair of supports spacedlaterally apart from one another by a conveyor opening and extendingbetween the frame upstream end and the frame downstream end along theconveyor axis. The supports engage laterally spaced apart tray undersidesurfaces of the plant cultivation trays supported on the conveyor. Thetray vents of the plant cultivation trays supported on the conveyor arelaterally intermediate the pair of tray supports and overlying theconveyor opening.

In some examples, the air delivery ductwork includes a plurality of ductassemblies for conducting air to the first and second ports. The ductassemblies are spaced vertically apart from one another, and theconveyor assemblies and the duct assemblies are vertically interposedbetween one another.

In some examples, the air delivery ductwork includes a duct header influid communication with each duct assembly for conducting air thereto.

In some examples, the duct assemblies include an upper duct assemblyabove the conveyor assemblies. The upper duct assembly includes at leastone upper duct having an upper duct bottom wall facing the conveyorassemblies and a set of the first ports in the upper duct bottom wallfor discharging air downwardly from the upper duct.

In some examples, the duct assemblies include a lower duct assemblybelow the conveyor assemblies. The lower duct assembly includes at leastone lower duct having a lower duct top wall facing the conveyorassemblies and a set of the second ports in the lower duct top wall fordischarging air upwardly from the lower duct.

In some examples, the duct assemblies include at least one intermediateduct assembly vertically intermediate an upper one of the conveyorassemblies above the intermediate duct assembly and a lower one of theconveyor assemblies below the intermediate duct assembly. Theintermediate duct assembly includes at least one intermediate ducthaving: an intermediate duct bottom wall facing the lower one of theconveyor assemblies, a set of the first ports in the intermediate ductbottom wall for discharging air downwardly from the intermediate duct,an intermediate duct top wall opposite the intermediate duct bottom walland facing the upper one of the conveyor assemblies, and a set of thesecond ports in the intermediate duct top wall for discharging airupwardly from the intermediate duct.

In some examples, the conveyor axis slopes downwards relative to ahorizontal plane from the frame upstream end to the frame downstream endfor urging translation of the plant cultivation trays along the conveyoraxis toward the frame downstream end via gravitational force. In someexamples, each conveyor assembly includes a plurality of ducts, witheach duct extending laterally across the conveyor assembliesperpendicular to the conveyor axis. The ducts of each duct assembly arespaced apart from one another along a conveyor assembly axis. Theconveyor assembly axis is parallel with the conveyor axis.

In some examples, each conveyor assembly includes a plurality of theconveyors mounted at a generally common elevation and arranged inside-by-side lanes, the conveyors of each conveyor assembly including afirst conveyor and a second conveyor spaced laterally apart from andextending parallel with the first conveyor. In some examples, the airdelivery ductwork includes one or more duct headers laterallyintermediate the first and second conveyors, a plurality of first ductassemblies extending laterally from a first side of the duct headers fordelivering air to plants held in trays supported on each first conveyor,and a plurality of second duct assemblies extending laterally from asecond side of the duct headers opposite the first side for deliveringair to plants held in trays supported on each second conveyor. In someexamples, the one or more duct headers include a first duct header influid communication with the first duct assemblies for conducting airthereto, and a second duct header in fluid communication with the secondduct assemblies for conducting air thereto. In some examples, the firstduct header is spaced axially apart from the second duct header. In someexamples, each duct header is oriented generally vertically, and eachduct assembly is oriented generally horizontally.

According to some aspects, a plant cultivation tray includes: (a) a traybody having a tray top and a tray bottom opposite the tray top; (b) anutrient chamber internal the tray body for holding plant nutrientsolution; (c) a plurality of plant cavities in the tray body for holdingplants, each plant cavity open to the tray top and in fluidcommunication with the nutrient chamber for providing the plant nutrientsolution to the plants; and (d) at least one tray vent passingvertically through the tray body and the nutrient chamber, the tray ventopen to the tray top and the tray bottom for passing air verticallythrough the tray body to facilitate delivery of air to the plants frombelow.

In some examples, the tray body includes a tray lower portion and a trayupper portion removably nested in the tray lower portion. The nutrientchamber is in the tray lower portion, the plant cavities are in the trayupper portion, and the tray vent passes through the tray lower portionand the tray upper portion.

In some examples, the tray body includes a nutrient chamber bottom walland a nutrient chamber sidewall extending upwardly from a periphery ofthe nutrient chamber bottom wall. The nutrient chamber bottom wall andthe nutrient chamber sidewall enclose the nutrient chamber.

In some examples, the tray vent includes a vent projection extendingupwardly from the nutrient chamber bottom wall and through the nutrientchamber. The vent projection includes a hollow vent interior in fluidisolation of the nutrient chamber, and a projection port above thenutrient chamber and providing fluid communication between the ventinterior and the tray top. In some examples, the vent projectionincludes a projection top wall above the nutrient chamber and aprojection sidewall extending between the chamber bottom wall and theprojection top wall. The projection sidewall horizontally encloses thevent interior and the projection port is in the projection top wall.

According to some aspects, a method of cultivating plants in ahigh-density plant cultivation system includes: (a) supporting aplurality of plant cultivation trays on a conveyor assembly, each plantcultivation tray including a plurality of plant cavities holding plants,the plant cavities open to a tray top of the tray; (b) supplying plantnutrient solution to a nutrient chamber in each plant cultivation tray,the nutrient chamber in fluid communication with the plant cavities forproviding the plant nutrient solution to the plants; and (c) dischargingair upwardly from a plurality of ports in a duct and conducting the airvertically through the tray and to the plants from below via tray ventspassing vertically through each nutrient chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings included herewith are for illustrating various examples ofapparatuses and methods of the present specification and are notintended to limit the scope of what is taught in any way. In thedrawings:

FIG. 1 is a perspective view of an example plant cultivation system;

FIG. 1A is a partially exploded view of the system of FIG. 1;

FIG. 2 is a side elevation view of the system of FIG. 1;

FIG. 3 is a schematic side view of a portion of the system of FIG. 1,showing plant cultivation trays supported on a conveyor of the system ofFIG. 1,

FIG. 4 is a rear elevation view of the system of FIG. 1;

FIG. 5 is a schematic rear view of a portion of the system of FIG. 1,showing a plant cultivation tray supported on a conveyor of the systemof FIG. 1;

FIG. 6 is a perspective view of a plant cultivation tray of the systemof FIG. 1;

FIG. 7 is a top view of the tray of FIG. 6;

FIG. 8 is a cross-sectional exploded view of the tray of FIG. 6 takenalong line 8-8 of FIG. 7;

FIG. 9 is a cross-sectional exploded view of the tray of FIG. 6 takenalong line 9-9 of FIG. 7;

FIG. 10 is a schematic cross-sectional rear view of a portion of thesystem of FIG. 1, taken along a cross-sectional line like line 8-8 ofFIG. 7;

FIG. 11 is a perspective top view of a tray lower portion of the tray ofFIG. 6;

FIG. 12 is a perspective bottom view of the tray lower portion of FIG.11;

FIG. 13 is a side elevation view of the tray lower portion of FIG. 11;

FIG. 14A is a schematic side elevation view of the system of FIG. 1,with an optional tray loader and an optional tray extractor shown inrespective first configurations;

FIG. 14B is a schematic side elevation view like that of FIG. 14A, butshowing the tray loader and the tray extractor in respective secondconfigurations;

FIG. 15 is a top perspective view of another example plant cultivationtray for a system like that of FIG. 1;

FIG. 16 is a perspective cross-sectional view of the tray of FIG. 15,taken along line 16-16 of FIG. 15;

FIG. 17 is a bottom perspective view of the tray of FIG. 15;

FIG. 18 is a top perspective view of a lower portion and raised floor ofthe tray of FIG. 15;

FIG. 19 is a top perspective view like that of FIG. 18, but with theraised floor removed;

FIG. 20 is a schematic side elevation view of another example plantcultivation system;

FIG. 21 is a perspective view of another example plant cultivationsystem;

FIG. 21A is a partially exploded view of the system of FIG. 21;

FIG. 22 is a cross-sectional view of a duct portion of the system ofFIG. 21, taken along line 22-22 of FIG. 21A;

FIG. 23 is a perspective view of another example plant cultivationsystem; and

FIG. 24 is a perspective view of an air delivery ductwork of the systemof FIG. 23.

DETAILED DESCRIPTION

Various apparatuses or processes will be described below to provide anexample of an embodiment of each claimed invention. No embodimentdescribed below limits any claimed invention and any claimed inventionmay cover processes or apparatuses that differ from those describedbelow. The claimed inventions are not limited to apparatuses orprocesses having all of the features of any one apparatus or processdescribed below or to features common to multiple or all of theapparatuses described below. It is possible that an apparatus or processdescribed below is not an embodiment of any claimed invention. Anyinvention disclosed in an apparatus or process described below that isnot claimed in this document may be the subject matter of anotherprotective instrument, for example, a continuing patent application, andthe applicants, inventors, or owners do not intend to abandon, disclaim,or dedicate to the public any such invention by its disclosure in thisdocument.

In the present application, the inventors disclose a high-density,vertically-stacked plant cultivation system that can facilitateproductive plant growth in indoor environments. The design aspectsdisclosed herein include features that can provide a more efficient,simple, cost-effective, and/or reliable cultivation system. Some of thefeatures disclosed herein provide for increased plant density for agiven overall volume of the system, in a way that overcomes challengesexperienced when trying to do so. For example, the inventors found anincreased density made it difficult to provide an optimal environmentfor plant growth for all plants cultivated in the system. Featuresdisclosed herein attempt to address this issue by helping to provide amore homogenous supply of air (including various gasses), nutrientsolution, and/or lighting to the plants being cultivated in the system.

Referring to FIGS. 1 and 1A, in the example illustrated, a plantcultivation system 100 includes a frame 102 having a frame upstream end102 a and a frame downstream end 102 b spaced horizontally apart fromthe frame upstream end 102 a. Referring to FIG. 2, in the exampleillustrated, a plurality of vertically stacked conveyor assemblies 104are mounted to the frame 102. Each conveyor assembly 104 includes atleast one conveyor 106 (see also FIG. 3) extending between the frameupstream end 102 a and the frame downstream end 102 b along a conveyoraxis 108. Referring to FIG. 4, in the example illustrated, each conveyorassembly 104 includes a plurality of the conveyors 106 mounted at agenerally common elevation and arranged in side-by-side lanes. In theexample illustrated, each conveyor assembly 104 includes three conveyors106.

Referring to FIGS. 2 and 3, in the example illustrated, a plurality ofplant cultivation trays 110 are supported on each conveyor 106 fortranslation along a respective conveyor axis 108 toward the framedownstream end 102 b. In the example illustrated, each of the conveyors106 supports six of the plant cultivation trays 110. The plantcultivation trays 110 are supported on each conveyor adjacent oneanother along the conveyor axis 108.

Referring to FIG. 6, in the example illustrated, each plant cultivationtray 110 includes a tray body 112 having a tray top 114 and a traybottom 115 vertically opposite the tray top 114 (see also FIG. 5). Eachtray 110 further includes a plurality of plant cavities 116 in the traybody 112 and open to the tray top 114. The plant cavities 116 are forholding plants (e.g. plants 118 shown in FIG. 5). In the exampleillustrated, each tray 110 includes thirty-six plant cavities 116arranged in a 6×6 array for holding thirty-six plants.

Referring to FIGS. 2 and 3, in the example illustrated, movement of thetrays 110 along each conveyor 106 is gravity driven, with the conveyoraxis 108 of each conveyor 106 sloping downwards relative to a horizontalplane 120 from the frame upstream end 102 a to the frame downstream end102 b. The horizontal plane 120 is normal to the force of gravity. Theplant cultivation trays 110 are rollingly supported on each conveyor 106and urged to translate along a respective conveyor axis 108 toward theframe downstream end 102 b via gravitational force. The conveyor axis108 can slope downwardly relative to the horizontal plane 120 at anangle of between about, for example, 0.5 and 5 degrees. In someexamples, the conveyor axis 108 slopes downwardly relative to thehorizontal plane 120 at an angle of between about 0.5 and 1.5 degrees.In the example illustrated, the conveyor axis 108 slopes downwardlyrelative to the horizontal plane 120 at an angle of about 1 degree.

Referring to FIG. 5, in the example illustrated, each conveyor 106includes a pair of supports 122 spaced laterally apart from one anotherby a conveyor opening 124. Referring to FIG. 3, in the exampleillustrated, each tray support 122 includes a rail 126 extending betweenthe frame upstream end 102 a and the frame downstream end 102 bgenerally parallel with a respective conveyor axis 108, and a pluralityof wheels 128 rotatably mounted to the rail 126 and spaced apart fromone another along the conveyor axis 108 for rollingly supporting thetrays 110 on the conveyor 106.

Referring still to FIG. 3, in the example illustrated, each plantcultivation tray 110 includes a tray front 130, a tray rear 132 axiallyopposite the tray front 130, and a pair of laterally spaced apart trayunderside surfaces 134 in engagement with the wheels 128 of the pair oftray supports 122 to rollingly support the tray 110 on the conveyor 106(see also FIG. 5). In the example illustrated, each underside surface134 of the tray 110 slopes downwards relative to the horizontal plane120 from the tray rear 132 to the tray front 130. When the plantcultivation trays 110 are supported on the conveyor 106, the trayunderside surfaces 134 of each tray 110 are generally parallel with theconveyor axis 108.

Referring to FIGS. 8 and 9, in the example illustrated, each plantcultivation tray 110 includes a nutrient chamber 136 internal the traybody 112 and in fluid communication with the plant cavities 116 (seealso FIGS. 10 and 11). The nutrient chamber 136 is for holding plantnutrient solution 138 (FIG. 10) to be provided to the plants 118 tofacilitate plant growth. In the example illustrated, the tray body 112includes a tray lower portion 112 a and a tray upper portion 112 bremovably nested in the tray lower portion 112 a. In the exampleillustrated, the nutrient chamber 136 is in the tray lower portion 112a, and the plant cavities 116 are in the tray upper portion 112 b. Thetray upper portion 112 b can be removed from the tray lower portion 112a to facilitate, for example, access to internal portions of the tray110, including, for example, the nutrient chamber 136. In the exampleillustrated, the plant cultivation tray 110 is of two-piececonstruction, and each of the tray lower portion 112 a and the trayupper portion 112 b is of integral, unitary, one-piece construction.

Referring still to FIGS. 8 and 9, in the example illustrated, the traybody 112 includes a nutrient chamber bottom wall 140 lying in a bottomwall plane 142 and a nutrient chamber sidewall 144 extending upwardlyfrom a periphery of the nutrient chamber bottom wall 140. The nutrientchamber bottom wall 140 and the nutrient chamber sidewall 144 enclosethe nutrient chamber 136 (see also FIGS. 10 and 11). In the exampleillustrated, the nutrient chamber bottom wall 140 is generally parallelwith the horizontal plane 120 when the tray 110 is supported on theconveyor 106 for maintaining a generally constant depth of the plantnutrient solution across the nutrient chamber bottom wall 140. This canfacilitate more homogenous nutrient uptake for each plant, across allcavities in the tray 110.

Referring to FIG. 8, in the example illustrated, the nutrient chamberbottom wall 140 is laterally intermediate and at an elevation below thetray underside surfaces 134. Referring to FIG. 10, when the plantcultivation tray 110 is supported on the conveyor 106, the nutrientchamber 136 is laterally intermediate the pair of tray supports 122, andextends into the conveyor opening 124.

Referring to FIG. 8, in the example illustrated, each plant cavity 116extends along a cavity axis 146 between a cavity top end 148 open to thetray top 114 and a cavity bottom end 150 below the cavity top end 148.In the example illustrated, the cavity axis 146 is normal to thehorizontal plane 120 when the tray 110 is supported on the conveyor 106.In the example illustrated, the cavity top ends 148 of the plantcavities 116 in each tray 110 lie in a common cavity top plane 152. Inthe example illustrated, the cavity top plane 152 is generally parallelwith the horizontal plane 120 (and the bottom wall plane 142) when thetray 110 is supported on the conveyor 106.

In the example illustrated, the cavity bottom ends 150 of the plantcavities 116 in each tray 110 lie in a common cavity bottom plane 154.In the example illustrated, the cavity bottom plane 154 is generallyparallel with the horizontal plane 120 (and the bottom wall plane 142)when the tray 110 is supported on the conveyor 106. In the exampleillustrated, each cavity bottom end 150 overlies the nutrient chamberbottom wall 140. Referring to FIG. 10, in the example illustrated, eachcavity bottom end 150 is in the nutrient chamber 136 when the tray upperportion 112 b is nested within the tray lower portion 112 a (see FIG.10).

Referring to FIG. 9, in the example illustrated, each plant cavity 116is enclosed by a cavity bottom wall 156 defining the cavity bottom end150, and a cavity sidewall 158 extending along the cavity axis 146between the cavity bottom wall 156 and the cavity top end 148. In theexample illustrated, the cavity bottom wall 156 is positioned in thenutrient chamber 136 when the tray upper portion 112 b is nested in thetray lower portion 112 a (see FIG. 10). At least one of the cavitybottom wall 156 and the cavity sidewall 158 has one or more perforations159 for providing fluid communication between the nutrient chamber 136and the plant cavity 116. In the example illustrated, each perforationpasses through the cavity bottom wall 156 and the cavity sidewall 158.In the example illustrated, the tray upper portion 112 b comprises thecavity bottom wall 156 and the cavity sidewall 158.

In the example illustrated, the cavity sidewall 158 includes a sidewalllower portion 160 extending from the cavity bottom wall 156 upwardlytoward the cavity top end 148, and a sidewall upper portion 162extending from the sidewall lower portion 160 to the cavity top end 148.In the example illustrated, the cavity bottom wall 156 and the sidewalllower portion 160 define a cavity lower portion 116 a for holding plantroots. In the example illustrated, the sidewall upper portion 162defines a cavity upper portion 116 b, and is for supporting plantcanopies of the plants (e.g. plant canopies 118 a of the plants 118shown in FIG. 10). In the example illustrated the sidewall upper portion162 has an upper portion inner surface 164 for engagement with lowerportions of the plant canopies to support and direct growth of the plantcanopies (see FIG. 10). In the example illustrated, the upper portioninner surface 164 is generally frustoconical, and flares radiallyoutwardly along the cavity axis 146 relative to the sidewall lowerportion 160, from the sidewall lower portion 160 to the cavity top end148.

Referring to FIG. 10, in the example illustrated, each tray 110 furtherincludes at least one tray vent 166 passing vertically through the traybody 112. Each tray vent 166 is open to the tray top 114 and the traybottom 115 for passing air vertically through the tray body 112 tofacilitate delivery of air to the plants 118 from below. In the exampleillustrated, each tray vent 166 passes through the tray lower portion112 a and the tray upper portion 112 b. In the example illustrated, eachtray vent 166 extends along a vent axis 168 between a vent top end 170open to the tray top 114 and a vent bottom end 172 open to the traybottom 115. In the example illustrated, the vent axis 168 is normal tothe horizontal plane 120 when the tray 110 is supported on the conveyor106. Referring to FIG. 6, in the example illustrated, the tray 110includes a plurality of the tray vents 166, with the tray vents 166interposed between the plant cavities 116. In the example illustrated,each tray 110 includes twenty-five tray vents 166 arranged in a 5×5array.

Referring to FIG. 9, in the example illustrated, the tray vents 166 passvertically through the nutrient chamber 136 (see also FIGS. 10 and 11).In the example illustrated, each tray vent 166 is spaced horizontallyinwardly from the nutrient chamber sidewall 144. In the exampleillustrated, each tray vent 166 includes a vent projection 174 extendingupwardly from the nutrient chamber bottom wall 140 and through thenutrient chamber 136. The vent projection 174 has a hollow vent interior176 in fluid isolation of the nutrient chamber 136, and a projectionport 182 above the nutrient chamber 136 and providing fluidcommunication between the vent interior 176 and the tray top 114. In theexample illustrated, the vent projection 174 includes a projection topwall 178 above the nutrient chamber 136 and a projection sidewall 180extending between the nutrient chamber bottom wall 140 and theprojection top wall 178. In the example illustrated, the projectionsidewall 180 horizontally encloses the vent interior 176, and theprojection port 182 is in the projection top wall 178. In the exampleillustrated, each tray vent 166 further includes a tray port 184 in thetray upper portion 112 b. In the example illustrated, the projectionport 182 provides fluid communication between the vent interior 176 andthe tray top 114 through the tray port 184. In the example illustrated,the tray upper portion 112 b is supported on the projection top walls178 when nested in the tray lower portion 112 a.

The plant cultivation system 100 can include an air handling system forproviding air (and other gases) to the plants to facilitate plantgrowth. Referring to FIG. 1A, in the example illustrated, the airhandling system includes an air delivery ductwork 190 for delivering airto the plants held in the trays 110. The air delivery ductwork 190 canbe in fluid communication with an air conditioner to receive conditionedair for delivery to the plants 118. The air can be conditioned to have,for example, a humidity, temperature, and/or concentration of gasesappropriate for optimizing growth of the plants being cultivated. Insome examples, the air can be conditioned to have an air temperature ofbetween about 20-25 degrees Celsius, a relative humidity of about65%+/−5%, and a carbon dioxide concentration of between about 1000 ppmto 1500 ppm.

Referring to FIG. 10, in the example illustrated, the air deliveryductwork 190 includes a plurality of first ports 192 above each plantcultivation tray 110 supported on the conveyor assemblies 104 fordischarging air from the air delivery ductwork 190 downwardly to deliverair to the plants 118 from above. The air delivery ductwork 190 furtherincludes a plurality of second ports 194 below each plant cultivationtray 110 supported on the conveyor assemblies 104 for discharging airfrom the air delivery ductwork 190 upwardly to deliver air to the plants118 from below via the tray vents 166. Delivering air to the plants 118from both above and below can help improve the air distributionthroughout the plant canopies 118 a of the plants 118, can help improveplant growth, and can help provide a homogenous environment for allplants passing through the plant cultivation system 100.

In the example illustrated, the tray vents 166 of the trays 110supported on the conveyor 106 are laterally intermediate the pair oftray supports 122 and overlying the conveyor opening 124. In the exampleillustrated, the upward discharge of air from the second ports 194passes upwardly through the conveyor opening 124 and the tray vents 166to deliver air to the plants 118 from below. In the example illustrated,the vent bottom end 172 of each tray vent 166 overlies at least one ofthe second ports 194 for receiving air discharged from the at least oneof the second ports 194.

Referring to FIG. 1A, in the example illustrated, the air deliveryductwork 190 includes a plurality of duct assemblies 196 for conductingair to the first and second ports 192, 194. The duct assemblies 196 arespaced vertically apart from one another. In the example illustrated,the conveyor assemblies 104 and the duct assemblies 196 are verticallyinterposed between one another (see e.g. FIGS. 1 and 2).

In the example illustrated, the air delivery ductwork 190 includes aduct header 202 in fluid communication with each duct assembly 196 forconducting air thereto. The duct header 202 can be in fluidcommunication with the air conditioner for receiving conditioned airtherefrom and conducting the conditioned air to each duct assembly 196.

In the example illustrated, each duct assembly 196 includes a pluralityof ducts 198 for conducting respective streams of air to the firstand/or second ports 192, 194. In the example illustrated, each ductassembly 196 includes six ducts 198. In the example illustrated, eachduct 198 extends laterally across the conveyor assemblies 104perpendicular to the conveyor axis 108. In the example illustrated, eachduct 198 extends along a respective horizontal duct axis 200 between aduct first end in fluid communication with the duct header 202 forreceiving air and a duct second end spaced horizontally apart from theduct first end. In the example illustrated, each duct axis 200 isgenerally perpendicular to the conveyor axes 108. In the exampleillustrated, the ducts 198 of each duct assembly 196 are spaced apartfrom one another along a respective duct assembly axis 197. In theexample illustrated, the duct assembly axis 197 is generally parallelwith the conveyor axis 108 (see also FIG. 2).

Referring still to FIG. 1A, in the example illustrated, the ductassemblies 196 include an upper duct assembly 196 a above a set of theconveyor assemblies 104. The upper duct assembly 196 a includes at leastone upper duct 198 a. Referring to FIG. 10, in the example illustrated,the upper duct 198 a includes an upper duct bottom wall 204 facing theset of the conveyor assemblies 104, and a set of the first ports 192 inthe upper duct bottom wall 204 for discharging air downwardly from theupper duct 198 a.

Referring to FIG. 1A, in the example illustrated, the duct assemblies196 further include a lower duct assembly 196 b below the set of theconveyor assemblies 104. The lower duct assembly 196 b includes at leastone lower duct 198 b. The lower duct 198 b includes a lower duct topwall 206 facing the set of the conveyor assemblies 104, and a set of thesecond ports 194 in the lower duct top wall 206 for discharging airupwardly from the lower duct 198 b.

Referring still to FIG. 1A, in the example illustrated, the ductassemblies 196 further include at least one intermediate duct assembly196 c vertically intermediate the upper and lower duct assemblies 196 a,196 b. Each intermediate duct assembly 196 c is vertically intermediatean upper one of the conveyor assemblies 104 above the intermediate ductassembly 196 c and a lower one of the conveyor assemblies 104 below theintermediate duct assembly 196 c. Each intermediate duct assembly 196 cincludes at least one intermediate duct 198 c. Referring to FIG. 10, inthe example illustrated, each intermediate duct 198 c includes anintermediate duct bottom wall 208 facing the lower one of the conveyorassemblies 104, and a set of the first ports 192 in the intermediateduct bottom wall 208 for discharging air downwardly from theintermediate duct 198 c. Each intermediate duct 198 c further includesan intermediate duct top wall 210 vertically opposite the intermediateduct bottom wall 208 and facing the upper one of the conveyor assemblies104, and a set of the second ports 194 in the intermediate duct top wall210 for discharging air upwardly from the intermediate duct 198 c.

In the example illustrated, the air handling system further includes anair recirculation system having a plurality of suction fans forsuctioning air from between the conveyor assemblies 104 and into an airrecirculation ductwork. The fans can be mounted to the frame verticallyintermediate and laterally outboard of the conveyor assemblies 104. Theair recirculation ductwork can conduct the suctioned air to the airconditioner for conditioning and delivery to the air delivery ductwork190.

Referring to FIG. 10, in the example illustrated, each plant cultivationtray 110 includes a nutrient chamber inlet 218 in the tray body 112 fordelivering plant nutrient solution to the nutrient chamber 136. In theexample illustrated, the tray lower portion 112 a includes an upperperipheral edge 113, and at least a portion of the upper peripheral edge113 is spaced laterally outwardly apart from the tray upper portion 112b by an inlet spacing 220. In the example illustrated, the nutrientchamber inlet 218 comprises the inlet spacing 220.

Referring to FIG. 11, in the example illustrated, the nutrient chambersidewall 144 includes a sidewall first portion 144 a extending axiallybetween the tray front 130 and the tray rear 132; a sidewall secondportion 144 b spaced laterally apart from the sidewall first portion 144a and extending axially between the tray front 130 and the tray rear132; a sidewall third portion 144 c extending laterally between thesidewall first and second portions 144 a, 144 b; and a sidewall fourthportion 144 d spaced axially apart from the sidewall third portion 144 cand extending laterally between the sidewall first and second portions144 a, 144 b.

In the example illustrated, the nutrient chamber inlet 218 includes anutrient delivery trough 222 internal the tray body 112 and separatedfrom the nutrient chamber 136 by the sidewall first portion 144 a (seealso FIG. 10). In the example illustrated, the delivery trough 222extends axially between the tray front and the tray rear 130, 132.Referring to FIG. 10, in the example illustrated, the inlet spacing 220is open to the nutrient delivery trough 222 for supplying the plantnutrient solution to the nutrient delivery trough 222.

Referring to FIG. 11, in the example illustrated, the nutrient chamberinlet 218 further includes a plurality of sidewall apertures 224 in thesidewall first portion 144 a. The sidewall apertures 224 are spacedapart from one another along an axial length of the sidewall firstportion 144 a for distributing plant nutrient solution from the nutrientdelivery trough 222 to the nutrient chamber 136 along the axial lengthof the sidewall first portion 144 a. In the example illustrated, eachsidewall aperture 224 is open to an upper end of the sidewall firstportion 144 a.

Referring to FIG. 10, in the example illustrated, each plant cultivationtray 110 includes a nutrient chamber outlet 226 in the tray body 112 fordraining plant nutrient solution from the nutrient chamber 136. In theexample illustrated, the nutrient chamber 136 is horizontallyintermediate the nutrient chamber inlet 218 and the nutrient chamberoutlet 226. This can facilitate flow of fresh plant nutrient solutionintroduced at the nutrient chamber inlet 218 across the width of thenutrient chamber 136 for absorption by the plants, after which thedepleted plant nutrient solution can flow out of the nutrient chamber136 via the nutrient chamber outlet 226. In the example illustrated, thenutrient chamber outlet 226 includes a plurality of drainage ports 228in the tray lower portion 112 a for draining plant nutrient solutionoverflowing from the nutrient chamber 136.

Referring to FIG. 11, in the example illustrated, the nutrient chamberoutlet 226 further includes a drainage trough 230 internal the tray body112 and separated from the nutrient chamber 136 by the sidewall secondportion 144 b. In the example illustrated, the drainage trough 230extends axially between the tray front 130 and the tray rear 132. In theexample illustrated, the drainage ports 228 are in the drainage trough230 for draining plant nutrient solution flowing over the sidewallsecond portion 144 b from the nutrient chamber 136 to the drainagetrough 230.

In the example illustrated, each of the sidewall first, second, third,and fourth portions 144 a, 144 b, 144 c, 144 d has a first, second,third, and fourth height, respectively above the nutrient chamber bottomwall 140. In the example illustrated, the second height of the sidewallsecond portion 144 b is less than the first, third, and fourth heightsof the sidewall first, third, and fourth portions 144 a, 144 c, 144 d.The second height of the sidewall second portion 144 b defines a heightof the nutrient chamber 136, and a depth of the plant nutrient solutionthat can be held in the nutrient chamber 136. In the exampleillustrated, the sidewall second portion 144 b has an upper edge 145defining an upper boundary of the nutrient chamber 136.

The system 100 can further include a nutrient handling system fordelivering the plant nutrient solution to the plant cultivation trays110. Referring to FIG. 10, in the example illustrated, the nutrienthandling system includes a nutrient delivery ductwork 234 (shownschematically in FIG. 10) having a plurality of nutrient delivery ports236 (one of which is shown schematically in FIG. 10). Each nutrientdelivery port 236 is adjacent to and in fluid communication with arespective nutrient chamber inlet 218 for delivering plant nutrientsolution thereto.

In the example illustrated, the nutrient handling system can furtherinclude a nutrient recirculation system for recirculating the plantnutrient solution discharged from the nutrient chamber 136. The nutrientrecirculation system can include a nutrient recirculation ductworkincluding a plurality of collection troughs 242 for capturing plantnutrient solution flowing out from the nutrient chamber outlet 226. Inthe example illustrated, each collection trough 242 is mounted to theframe 102 and has an open top extending below the drainage ports 228 ofthe trays 110 supported on a respective conveyor 106.

Referring to FIG. 11, in the example illustrated, the tray lower portion112 a includes a plurality of baffles 244 in the nutrient chamber 136.The baffles 244 can help suppress slosh of plant nutrient solution inthe nutrient chamber 136, can facilitate distribution of plant nutrientsolution across the nutrient chamber 136, and may help direct rootgrowth of the plants. In the example illustrated, the baffles 244 arespaced axially apart from one another, and each baffle 244 extendsupwardly from the nutrient chamber bottom wall 140 and laterally betweenthe first and second sidewall portions 144 a, 144 b of the nutrientchamber sidewall 144. In the example illustrated, the baffles 244comprise lower portions of the projection sidewalls 180 of the ventprojections 174.

In the example illustrated, the nutrient chamber 136 comprises aplurality of lateral channels 246 extending laterally between thesidewall first and second portions 144 a, 144 b. The lateral channels246 are separated axially from one another by the baffles 244. In theexample illustrated, each sidewall aperture 224 of the nutrient chamberinlet 218 is open to a respective lateral channel 246 (see also FIG. 9),and is axially intermediate a respective pair of axially adjacentbaffles 244. Referring to FIG. 9, in the example illustrated, the cavitybottom end 150 of each plant cavity 116 is axially intermediate arespective pair of axially adjacent baffles 244, and is positioned in arespective lateral channel 246 of the nutrient chamber 136 when the trayupper portion 112 b is nested in the tray lower portion 112 a (see alsoFIG. 10).

Referring to FIG. 11, in the example illustrated, the plurality ofbaffles 244 includes a set of first baffles 244 a extending laterallyfrom the sidewall first portion 144 a toward the sidewall second portion144 b, and a set of second baffles 244 b extending laterally from thesidewall second portion 144 b toward the sidewall first portion 144 a.The first baffles 244 a and the second baffles 244 b are axiallyinterposed between one another.

In the example illustrated, the nutrient chamber 136 further includes aplurality of axial channels 248 extending axially across the baffles 244for providing fluid communication between the lateral channels 246. Inthe example illustrated, the plurality of axial channels 248 includes aplurality of first axial channels 248 a extending across the firstbaffles 244 a laterally intermediate the first baffles 244 a and thesidewall second portion 144 b, and a plurality of second axial channels248 b extending across the second baffles 244 b laterally intermediatethe second baffles 244 b and the sidewall first portion 144 a.

The system 100 can further include a plant lighting system for providinghomogenous lighting for all the plants being cultivated in the system100 to facilitate plant growth. Referring to FIG. 10, in the exampleillustrated, the plant lighting system includes one or more lights 252(e.g. LED lights) mounted above each plant cultivation tray 110.

Referring to FIGS. 14A and 14B, the system can optionally include anautomated tray loader 254 adjacent the frame upstream end 102 a forloading the plant cultivation trays 110 onto the conveyor assemblies104. In the example illustrated, the tray loader 254 includes at leastone loader carriage 256 movable between a loader first position (FIG.14A) for receiving at least one plant cultivation tray 110, and at leastone loader second position (FIG. 14B) spaced apart from the loader firstposition for loading the at least one plant cultivation tray 110 ontothe conveyor assemblies 104 from the frame upstream end 102 a. In theexample illustrated, the loader first position and the loader secondposition are spaced vertically apart from one another.

In the example illustrated, the loader carriage 256 supports the plantcultivation trays 110 with the bottom wall plane 142 parallel with thehorizontal plane 120. The tray loader 254 further includes a loaderactuator 258 moveable between a loader closed position (FIG. 14A) forretaining the plant cultivation trays 110 in the loader carriage 256,and a loader open position (FIG. 14B) for releasing the plantcultivation trays 110 from the loader carriage 256 and onto respectiveconveyors 106. Referring to FIG. 14B, in the example illustrated, whenthe loader carriage 256 is in the loader second position and the loaderactuator 258 is in the loader open position, the trays 110 in the loadercarriage 256 are urged to translate from the loader carriage 256 andonto respective conveyors 106 via gravitational force.

The system 100 can optionally include a tray locking system 260 forinhibiting translation of the plant cultivations trays 110 supported onthe conveyors 106. In the example illustrated, the locking system 260includes a tray lock actuator 262 for each conveyor 106 adjacent theframe downstream end 102 b. Each tray lock actuator 262 is movablebetween a locked position (shown in FIG. 14B with respect to bothconveyors 106) for engagement with a respective plant cultivation tray110 nearest the frame downstream end 102 b to inhibit translation of theplant cultivation trays 110 supported on the conveyor 106, and anunlocked position (shown in FIG. 14A with respect to the upper conveyor106) clear of the trays 110 for permitting translation of the trays 110along the conveyor axis 108 toward the frame downstream end 102 b viagravitational force.

The system 100 can optionally include an automated tray extractor 264adjacent the frame downstream end 102 b for extracting the plantcultivations trays 110 from the conveyor assemblies 104. The trayextractor 264 includes at least one extractor carriage 266 movablebetween an extractor first position (FIG. 14A) for extracting at leastone plant cultivation tray 110 from the conveyor assemblies 104 at theframe downstream end 102 b, and an extractor second position (FIG. 14B)spaced apart from the extractor first position for unloading the atleast one plant cultivation tray 110 from the extractor carriage 266. Inthe example illustrated, the extractor first position and the extractorsecond position are spaced vertically apart from one another.

In the example illustrated, the extractor carriage 266 supports theplant cultivation trays 110 with the bottom wall plane 142 parallel withthe horizontal plane 120. The tray extractor 264 further includes anextractor actuator 268 moveable between an extractor closed position(FIG. 14A) for retaining the plant cultivation trays 110 in theextractor carriage 266, and an extractor open position (FIG. 14B) forreleasing the plant cultivation trays 110 from the extractor carriage266. Referring to FIG. 14B, in the example illustrated, when theextractor carriage 266 is in the extractor second position and theextractor actuator 268 is in the extractor open position, the trays 110in the extractor carriage 266 are urged to translate out from theextractor carriage 266 via gravitational force.

Operation of the system 100 will now be described with respect to asingle conveyor 106. A plurality of the plant cultivation trays 110 areloaded onto the conveyor 106 at the frame upstream end 102 a via thetray loader 254. The loaded trays 110 translate along the conveyor axis108 toward the frame downstream end 102 b via gravitational force, andare held at respective first locations along the conveyor axis 108adjacent one another via the locking system 260. Plant nutrient solutionis delivered to the nutrient chambers 136 of the trays 110, air isdischarged downwardly from the first ports 192 and upwardly from thesecond ports 194 and delivered to the plants 118 from above and below,and light is provided to the plants 118 from above.

After a defined amount of time, the extractor carriage 266 is moved tothe extractor second position and the lock actuator 262 is moved to theunlocked position. The trays 110 on the conveyor 106 translate viagravitational force further toward the frame downstream end 102 b, withthe tray 110 at the frame downstream end 102 b translating into theextractor carriage 266, and the remaining trays 110 translating towardthe frame downstream end 102 b into respective second locations alongthe conveyor axis 108. The tray lock actuator 262 is moved to the lockedposition to hold the trays 110 supported on the conveyor 106 at therespective second locations. As each tray 110 is extracted from theframe downstream end 102 b, another tray 110 can be loaded onto theconveyor 106 from the frame upstream end 102 a.

The extractor carriage 266 holding the extracted tray 110 is moved fromthe extractor first position to the extractor second position. Once theextractor carriage 266 is in the extractor second position, theextractor actuator 268 is moved from the extractor closed position tothe extractor open position for unloading the extracted tray 110 fromthe extractor carriage 266 for further handling. The plants in the trays110 remaining on the conveyor 106 can receive further nutrients, air,and light, and/or the remaining trays 110 can be extracted for furtherhandling and replaced with another set of trays 110.

Referring to FIG. 15, an example of another plant cultivation tray 1110for a plant cultivation system like the system 100 is illustratedschematically. The tray 1110 has similarities to the tray 110, and likefeatures are identified by like reference characters, incremented by1000.

In the example illustrated, the plant cultivation tray 1110 includes atray body 1112 having a tray top 1114 and a tray bottom 1115 verticallyopposite the tray top 1115. The tray 1110 further includes a pluralityof plant cavities 1116 in the tray body 1112 and open to the tray top1114. In the example illustrated, the tray 1110 includes four plantcavities 1116 arranged in a 2×2 array.

Referring to FIG. 16, in the example illustrated, the tray 1110 furtherincludes a nutrient chamber 1136 internal the tray body 1112 (see alsoFIGS. 18 and 19) and in fluid communication with the plant cavities1116. In the example illustrated, the tray body 1112 further includes atleast one first tray vent 1166 a passing vertically through the traybody 1112. The first tray vent 1166 a is open to the tray top 1114 andthe tray bottom 1115 for passing air through the tray body 1112 tofacilitate delivery of air to the plants held in the tray 1110 frombelow. In the example illustrated, the first tray vent 1166 a passesvertically through the nutrient chamber 1136. In the exampleillustrated, the tray 1110 include a single first tray vent 1166 acentered horizontally between the plant cavities 1116.

In the example illustrated, the tray 1110 further includes a pluralityof second tray vents 1166 b passing vertically through the tray body1112. Each second tray vent 1166 b is open to the tray top 1114 and thetray bottom 1115 for passing air through the tray body 1112 tofacilitate delivery of air to the plants held in the tray 1110 frombelow. Referring to FIG. 15, in the example illustrated, the tray 1110includes a tray sidewall 1270 extending between the tray top 1114 andthe tray bottom 1115. The tray sidewall 1270 has a horizontallyoutwardly directed sidewall outer surface 1272 and a plurality of ventrecesses 1274 extending horizontally inward of the sidewall outersurface 1272 and open to the tray top 1114 and the tray bottom 1115. Inthe example illustrated, the second tray vents 1166 b comprise the ventrecesses 1274.

Referring to FIG. 16, in the example illustrated, the tray sidewall 1270includes a sidewall front portion 1270 a at a tray front 1130 of thetray 1110, a sidewall rear portion 1270 b (FIG. 15) at a tray rear 1132(FIG. 15) of the tray 1110 and axially opposite the sidewall frontportion 1270 a, a sidewall left portion 1270 c extending between thesidewall front and rear portions 1270 a, 1270 b, and a sidewall rightportion 1270 d laterally opposite the sidewall left portion 1270 c andextending between the sidewall front and rear portions 1270 a, 1270 b.

In the example illustrated, the vent recesses 1274 include at least onefront vent recess 1274 a in the sidewall front portion 1270 a and atleast one rear vent recess 1274 b (FIG. 15) in the sidewall rear portion1270 b. When a plurality of the trays 1110 are positioned axiallyadjacent one another (e.g. when the trays 1110 are supported on aconveyor), the front and rear vent recesses 1274 a, 1274 b of axiallyadjacent trays 1110 are open to and in registration with one another tofacilitate delivery of air upwardly therethrough.

Referring still to FIG. 16, in the example illustrated, the ventrecesses 1274 further include at least one left vent recess 1274 c inthe sidewall left portion 1270 c and at least one right vent recess 1274d in the sidewall right portion 1270 d. When the trays 1110 aresupported laterally adjacent one another (e.g. when the trays 1110 aresupported on side-by-side conveyors), the left and right vent recesses1274 c, 1274 d of laterally adjacent trays 1110 are open to and inregistration with one another to facilitate delivery of air upwardlytherethrough.

Referring to FIG. 17, in the example illustrated, the tray 1100 includesa pair of laterally spaced apart tray underside surfaces 1134 forengagement with wheels of a gravity conveyor (e.g. like the gravityconveyor 106) to rollingly support the tray 1110 on the conveyor. In theexample illustrated, when the tray is supported on the gravity conveyor,each underside surface 1134 slopes downwards relative to a horizontalplane from the tray rear 1132 to the tray front 1130.

Referring to FIG. 19, in the example illustrated, the tray body 1112includes a nutrient chamber bottom wall 1140 lying in a bottom wallplane and a nutrient chamber sidewall 1144 extending upwardly from aperiphery of the nutrient chamber bottom wall 1140. The nutrient chamberbottom wall 1140 and the nutrient chamber sidewall 1144 enclose thenutrient chamber 1136. In the example illustrated, the nutrient chamberbottom wall 1140 is generally parallel with the horizontal plane whenthe tray 1110 is supported on the conveyor for maintaining a generallyconstant depth of the plant nutrient solution across the nutrientchamber bottom wall 1140.

Referring to FIG. 16, in the example illustrated, the tray body 1112includes a tray lower portion 1112 a and a tray upper portion 1112 bremovably nested in the tray lower portion 1112 a. In the exampleillustrated, the nutrient chamber 1136 is in the tray lower portion 1112a, and the plant cavities 1116 are in the tray upper portion 1112 b.

Referring still to FIG. 16, in the example illustrated, the plantcultivation tray 1110 includes a nutrient chamber inlet 1218 in the traybody 1112 for delivering plant nutrient solution to the nutrient chamber1136. In the example illustrated, the nutrient chamber inlet 1218comprises a plurality of inlet ports 1278 in the tray upper portion 1112b. In the example illustrated, the inlet ports 1278 are above and opento the nutrient chamber 1136.

In the example illustrated, the plant cultivation tray 1110 furtherincludes a nutrient chamber outlet 1226 in the tray body 1112 fordraining plant nutrient solution overflowing from the nutrient chamber1136. In the example illustrated, the nutrient chamber outlet 1226comprises at least one drainage port 1228 in the tray lower portion 1112a. In the example illustrated, the tray lower portion 1112 a includes ahollow drainage projection 1280 extending upwardly from the nutrientchamber bottom wall 1140 and through the nutrient chamber 1136 (see alsoFIG. 19). The drainage projection 1280 includes a drainage top wall 1282above the nutrient chamber bottom wall 1140, and a drainage sidewall1284 extending between the chamber bottom wall 1140 and the drainage topwall 1282. In the example illustrated, the drainage port 1228 passesvertically through the drainage top wall 1282 and is open to the traybottom 1115 (see also FIG. 17).

Referring to FIG. 18, in the example illustrated, the plant cultivationtray 1110 further includes an optional raised floor 1286 nested in thenutrient chamber 1136 and spaced above the nutrient chamber bottom wall1140. In the example illustrated, the raised floor 1286 includes a floorfirst portion 1286 a vertically intermediate the nutrient chamber bottomwall 1140 and the plant cavities 1116, and a floor second portion 1286 boverlying the nutrient chamber outlet 1226 to isolate the nutrientchamber outlet 1226 from the plant cavities 1116 (see also FIG. 16).This can help inhibit blockage of the nutrient chamber outlet 1226 byplant roots extending into the nutrient chamber 1136.

Referring to FIG. 16, in the example illustrated, the floor firstportion 1286 a vertically separates the nutrient chamber 1136 into alower volume 1136 a below the floor first portion 1286 a and an uppervolume 1136 b above the floor first portion 1286 a and in fluidcommunication with the upper volume 1226 b via one or more flooropenings 1288 (FIG. 18). In the example illustrated, the plant cavities1116 are in fluid communication with the upper volume 1236 b of thenutrient chamber 1136. In the example illustrated, the floor firstportion 1286 a lies in a floor plane that is generally parallel with thehorizontal plane when the tray 1110 is supported on the conveyor.

Referring to FIG. 19, in the example illustrated, the plant cultivationtray 1110 further includes a plurality of baffles 1244 in the nutrientchamber 1136. In the example illustrated, the baffles 1244 extendupwardly from the nutrient chamber bottom wall 1140, and are verticallyintermediate the nutrient chamber bottom wall 1140 and the raised floor1286.

Referring to FIG. 16, in the example illustrated, the tray upper portion1112 b is of multi-piece construction, and includes a frame 1290supported by the tray lower portion 1112 a and a plurality of plant pots1292 removably mounted to the frame 1290 and enclosing respective plantcavities 1116.

Referring to FIG. 20, an example of another plant cultivation system2100 is illustrated schematically. The system 2100 has similarities tothe system 100, and like features are identified by like referencecharacters, incremented by 2000.

In the example illustrated, the system 2100 includes a plurality offrames 2102. Each frame 2102 has a frame upstream end 2102 a and a framedownstream end 2102 b spaced horizontally apart from the frame upstreamend 2102 a. The frames 2102 are positioned in series with the downstreamend 2102 b of a first one of the frames 2102 adjacent an upstream end2102 a of a second one of the frames 2102.

In the example illustrated, the system 2100 further includes a pluralityof vertically stacked conveyor assemblies 2104 mounted to each frame2102. Each conveyor assembly 2104 includes at least one gravity conveyor2106 extending between the frame upstream end 2102 a and the framedownstream end 2102 b along a respective conveyor axis 2108. In theexample illustrated, the conveyor axis 2108 slopes downwards relative toa horizontal plane 2120 from the frame upstream end 2102 a to the framedownstream end 2102 b.

In the example illustrated, the system 2100 further includes a pluralityof plant cultivation trays 2110 rollingly supported on each conveyor2106 and urged to translate along a respective conveyor axis 2108 towardthe frame downstream end 2102 b via gravitational force. Each plantcultivation tray 2110 includes a tray body having a tray top and a traybottom vertically opposite the tray top. Each tray further includes aplurality of plant cavities 2116 in the tray body and open to the traytop. The plant cavities 2116 are for holding plants.

In the example illustrated, the system 2100 further includes anautomated tray transfer mechanism 2280 axially intermediate thedownstream end 2102 b of the first one of the frames 2102 and theupstream end 2102 a of the second one of the frames 2102. The traytransfer mechanism 2280 includes at least one transfer carriage 2282movable between a receiving position (shown in solid lines) forreceiving at least one tray 2110 from the conveyor assemblies 2104mounted to the first one of the frames 2102, and a transfer position(shown in phantom lines) above the receiving position for loading the atleast one tray 2110 onto the conveyor assemblies 2104 mounted to thesecond one of the frames 2102.

Referring to FIG. 21, an example of another plant cultivation system3100 is illustrated schematically. The system 3100 has similarities tothe system 100, and like features are identified by like referencecharacters, incremented by 3000.

In the example illustrated, the plant cultivation system 3100 includes aframe 3102 and a plurality of vertically stacked conveyor assemblies3104 mounted to the frame 3102. A plurality of plant cultivation trays3110 are supported on each conveyor 3106 of the assemblies 3104 fortranslation along a respective conveyor axis.

Referring to FIG. 21A, in the example illustrated, the plant cultivationsystem 3100 includes an air handling system having an air deliveryductwork 3190 for delivering air to plants held in the trays 3110. Inthe example illustrated, the air delivery ductwork 3190 includes aplurality of first ports 3192 (FIG. 22) above each plant cultivationtray 3110 supported on the conveyor assemblies 3104 for discharging airfrom the air delivery ductwork 3190 downwardly to deliver air to theplants from above. In some examples, each first port 3192 can be inalignment with (and overlie) a respective plant cavity (and in someexamples, a head of a respective plant held in the cavity). The airdelivery ductwork 3190 further includes a plurality of second ports 3194below each plant cultivation tray 3110 supported on the conveyorassemblies 3104 for discharging air from the air delivery ductwork 3190upwardly to deliver air to the plants from below (e.g. through trayvents). In some examples, the second ports may be omitted.

In the example illustrated, the air delivery ductwork 3190 includes aplurality of vertically spaced apart duct assemblies 3196 for conductingair to the first and second ports 3192, 3194 (FIG. 22), and a ductheader 3202 in fluid communication with each duct assembly 3196 forconducting air thereto. In the example illustrated, each duct assembly3196 includes a plurality of ducts 3198 for conducting respectivestreams of air to the first and/or second ports. In the exampleillustrated, each duct assembly 3196 includes eighteen ducts 3198.Referring to FIG. 22, in the example illustrated, each duct 3198comprises a tube having a generally circular cross-section. Providingtubular ducts may help to, for example, reduce manufacturing costs ofthe air delivery ductwork 3190.

Referring still to FIG. 22, in the example illustrated, each duct 3198includes a duct bottom wall 3208 and a duct top wall 3210 verticallyopposite the duct bottom wall 3208. In the example illustrated, a set ofthe first ports 3192 are provided in the duct bottom wall 3208 fordischarging air downwardly from the duct 3198, and a set of the secondports 3194 are provided in the duct top wall 3210 for discharging airupwardly from the duct 3198. In the example illustrated, each duct 3198includes sidewalls 3211 extending between the bottom and top walls 3208and 3210, and optionally, a set of side ports 3195 in the sidewalls fordischarging air sideways from the duct 3198.

Referring to FIG. 23, an example of another plant cultivation system4100 is shown. The system 4100 has similarities to the system 100, andlike features are identified by like reference characters, incrementedby 4000.

In the example illustrated, the system 4100 includes a frame 4102 and aplurality of vertically stacked conveyor assemblies 4104 mounted to theframe 4102. Each conveyor assembly 4104 includes a plurality ofconveyors 4106 each extending along a conveyor axis 4108 for supportinga plurality of plant cultivation trays 4110. In the example illustrated,the conveyors 4106 of each conveyor assembly 4104 are mounted at agenerally common elevation and arranged in side-by-side lanes, andinclude a first conveyor 4106 a and a second conveyor 4106 b spacedlaterally apart from and extending parallel with the first conveyor 4106a. In the example illustrated, each conveyor assembly 4104 furtherincludes a third conveyor 4106 c laterally outboard of the firstconveyor 4106 a, and a fourth conveyor 4106 d laterally outboard of thesecond conveyor 4106 b.

In the example illustrated, the plant cultivation system 4100 furtherincludes an air handling system comprising an air delivery ductwork 4190for delivering air to plants held in the trays 4110 supported on theconveyors 4106. In the example illustrated, the air delivery ductwork4190 includes one or more duct headers 4202 laterally intermediate thefirst and second conveyors 4106 a, 4106 b, a plurality of first ductassemblies 4196 a (FIG. 24) extending laterally from a first side of theduct headers 4202 for delivering air to plants held in trays 4110supported on each first conveyor 4106 a (and each third conveyor 4106 cin the example illustrated), and a plurality of second duct assemblies4196 b (FIG. 24) extending laterally from a second side of the ductheaders 4202 opposite the first side for delivering air to plants heldin trays 4110 supported on each second conveyor 4106 b (and each fourthconveyor 4106 d in the example illustrated).

Positioning the duct headers 4202 between the first and second conveyors4106 a, 4106 b can help to, for example, provide the system 4100 withgenerally open sides that are generally free of obstructions. This mayfacilitate more convenient access to the conveyors 4106 and/or othersystem components, particularly in plant cultivation systems thatinclude wide conveyor assemblies (for example, conveyor assemblies witha high number of side-by-side conveyors, or with wide conveyors). Thismay help with, for example, cleaning and/or sanitizing, inspection,maintenance, and/or component adjustment or replacement.

Referring to FIG. 24, in the example illustrated, the one or more ductheaders 4202 include a first duct header 4202 a in fluid communicationwith the first duct assemblies 4196 a for conducting air thereto, and asecond duct header 4202 b in fluid communication with the second ductassemblies 4196 b for conducting air thereto. In the exampleillustrated, the first duct header 4202 a is spaced axially apart fromthe second duct header 4202 b. In the example illustrated, the first andsecond duct headers 4202 a, 4202 b are oriented generally vertically forconducting air in a generally vertical direction (laterally intermediatethe first and second conveyors 4106 a, 4106 b), and the first and secondduct assemblies 4196 a, 4196 b are oriented generally horizontally forconducting air in a generally horizontal direction (above and/or belowthe conveyor assemblies 4104).

Referring to FIG. 23, the system 4100 further includes an automated trayloader 4254 adjacent a frame upstream end 4102 a for loading the plantcultivation trays 4110 onto the conveyor assemblies 4104. In the exampleillustrated, the tray loader 4254 includes at least one loader carriage4256 movable between a loader first position for receiving at least oneplant cultivation tray 4110, and at least one loader second positionspaced vertically apart from the loader first position for loading theat least one plant cultivation tray 4110 onto the conveyor assemblies4104 from the frame upstream end 4102 a. In some examples, the system4100 may also include an automated tray extractor (like the extractor264) and/or an automated tray transfer mechanism (like the mechanism2280) at a frame downstream end 4102 b of the frame 4102.

1. A gravity-driven plant cultivation system, comprising: (a) a framehaving a frame upstream end and a frame downstream end spacedhorizontally apart from the frame upstream end; (b) a plurality ofvertically stacked conveyor assemblies mounted to the frame, eachconveyor assembly including at least one gravity conveyor extendingbetween the frame upstream end and the frame downstream end along aconveyor axis, the conveyor axis sloping downwards relative to ahorizontal plane from the frame upstream end to the frame downstreamend; and (c) a plurality of plant cultivation trays rollingly supportedon each gravity conveyor and urged to translate along a respectiveconveyor axis toward the frame downstream end via gravitational force,each tray including: (i) a tray body having a tray top and a tray bottomvertically opposite the tray top; (ii) a plurality of plant cavities inthe tray body and open to the tray top, the plant cavities for holdingplants; and (iii) a nutrient chamber internal the tray body and in fluidcommunication with the plant cavities, the nutrient chamber for holdingplant nutrient solution.
 2. The system of claim 1, wherein each gravityconveyor includes a pair of supports spaced laterally apart from oneanother by a conveyor opening, each tray support including a railextending between the frame downstream end and the frame upstream endgenerally parallel with a respective conveyor axis, and a plurality ofwheels rotatably mounted to the rail and spaced apart from one anotheralong the conveyor axis, the wheels of the pair of supports engaginglaterally spaced apart tray underside surfaces of the plant cultivationtrays supported on the conveyor, each tray underside surface slopingdownwardly relative to the horizontal plane generally parallel with theconveyor axis.
 3. The system of claim 1, wherein the tray body includesa nutrient chamber bottom wall lying in a bottom wall plane and anutrient chamber sidewall extending upwardly from a periphery of thenutrient chamber bottom wall, the nutrient chamber bottom wall and thenutrient chamber sidewall enclosing the nutrient chamber, and whereinthe nutrient chamber bottom wall is generally parallel with thehorizontal plane for maintaining a generally constant depth of the plantnutrient solution across the nutrient chamber bottom wall.
 4. The systemof claim 3, wherein the nutrient chamber is laterally intermediate thepair of tray supports.
 5. The system of claim 4, wherein the nutrientchamber extends into the conveyor opening.
 6. The system of claim 1,wherein each tray includes at least one tray vent passing through thetray body, the tray vent extending along a vertical vent axis normal tothe horizontal plane between a vent top end open to the tray top and avent bottom end open to the tray bottom, the tray vent for passing airthrough the tray body to facilitate delivery of air to the plants frombelow.
 7. The system of claim 6, wherein the tray vent passes throughthe nutrient chamber.
 8. The system of claim 6, further comprising anair delivery ductwork for delivering air to the plants, the air deliveryductwork including a plurality of first ports above each plantcultivation tray for discharging air from the air delivery ductworkdownwardly to deliver air to the plants from above, and a pluralitysecond ports below each plant cultivation tray for discharging air fromthe air delivery ductwork upwardly to deliver air to the plants frombelow via the tray vents.
 9. A plant cultivation tray for agravity-driven plant cultivation system, comprising: (a) a tray bodyhaving a tray top, a tray bottom vertically opposite the tray top, atray front, and a tray rear axially opposite the tray front, the traybody including: (i) a pair of laterally spaced apart tray undersidesurfaces for engagement with wheels of a gravity conveyor to rollinglysupport the plant cultivation tray thereon, each underside surfacesloping downwards relative to a horizontal plane from the tray rear tothe tray front when the tray is supported on the conveyor; (ii) anutrient chamber bottom wall lying in a bottom wall plane; (iii) anutrient chamber sidewall extending upwardly from a periphery of thechamber bottom wall, the nutrient chamber bottom wall and the nutrientchamber sidewall enclosing a nutrient chamber internal the tray body forholding plant nutrient solution, wherein the nutrient chamber bottomwall is generally parallel with the horizontal plane when the tray issupported on the conveyor for maintaining a generally constant depth ofthe plant nutrient solution across the nutrient chamber bottom wall; and(b) a plurality of plant cavities in the tray body for holding plants,the plant cavities open to the tray top and in fluid communication withthe nutrient chamber for providing the plant nutrient solution to theplants.
 10. The tray of claim 9, wherein the nutrient chamber bottomwall is laterally intermediate and at an elevation below the undersidesurfaces.
 11. The tray of claim 9, wherein each tray includes at leastone tray vent passing through the tray body, the tray vent extendingalong a vertical vent axis normal to the horizontal plane between a venttop end open to the tray top and a vent bottom end open to the traybottom, the tray vent for passing air through the tray body tofacilitate delivery of air to the plants from below.
 12. The tray ofclaim 11, wherein the tray vent passes through the nutrient chamber. 13.The tray of claim 9, wherein each plant cavity extends along a verticalcavity axis normal to the horizontal plane between a cavity top end opento the tray top and a cavity bottom end below the cavity top end, andwherein the cavity bottom end of each plant cavity lies in a commoncavity bottom plane, the cavity bottom plane generally parallel with thehorizontal plane when the tray is supported on the conveyor.
 14. A plantcultivation system, comprising: (a) a frame having a frame upstream endand a frame downstream end spaced horizontally apart from the frameupstream end; (b) a plurality of vertically stacked conveyor assembliesmounted to the frame, each conveyor assembly including at least oneconveyor extending between the frame upstream end and the framedownstream end along a conveyor axis; (c) a plurality of plantcultivation trays supported on each conveyor for translation along arespective conveyor axis toward the frame downstream end, each plantcultivation tray including: a tray body having a tray top and a traybottom vertically opposite the tray top; a plurality of plant cavitiesin the tray body and open to the tray top, the plant cavities forholding plants; and at least one tray vent passing vertically throughthe tray body, the tray vent open to the tray top and the tray bottomfor passing air vertically through the tray body to facilitate deliveryof air to the plants from below; and (d) an air delivery ductwork fordelivering air to the plants, the air delivery ductwork including aplurality of first ports above each plant cultivation tray fordischarging air from the air delivery ductwork downwardly to deliver airto the plants from above, and a plurality second ports below each plantcultivation tray for discharging air from the air delivery ductworkupwardly to deliver air to the plants from below via the tray vents. 15.The system of claim 14, wherein the tray vent extends between a vent topend open to the tray top and a vent bottom end open to the tray bottom,and wherein the vent bottom end overlies at least one of the secondports for receiving air discharged from the at least one of the secondports.
 16. The system of claim 14, wherein each plant cultivation trayincludes a nutrient chamber internal the tray body and in fluidcommunication with the plant cavities, the nutrient chamber for holdingplant nutrient solution, and wherein the tray vent passes verticallythrough the nutrient chamber.
 17. The system of claim 14, wherein eachtray includes a tray sidewall extending between the tray top and thetray bottom, the tray sidewall having a horizontally outwardly directedsidewall outer surface and at least one vent recess extendinghorizontally inward of the sidewall outer surface and open to the traytop and the tray bottom, and wherein the tray vent comprises the ventrecess.
 18. The system of claim 14, wherein each conveyor includes apair of supports spaced laterally apart from one another by a conveyoropening and extending between the frame upstream end and the framedownstream end along the conveyor axis, the supports engaging laterallyspaced apart tray underside surfaces of the plant cultivation trayssupported on the conveyor, and wherein the tray vents of the plantcultivation trays supported on the conveyor are laterally intermediatethe pair of tray supports and overlying the conveyor opening.
 19. Thesystem of claim 14, wherein the air delivery ductwork includes aplurality of duct assemblies for conducting air to the first and secondports, the duct assemblies spaced vertically apart from one another, andthe conveyor assemblies and the duct assemblies vertically interposedbetween one another.
 20. The system of claim 19, wherein the airdelivery ductwork includes a duct header in fluid communication witheach duct assembly for conducting air thereto.